On 7 November 2019, the Government of the United Kingdom of Great Britain and Northern Ireland notified the Secretary-General that its ratification of the Convention would extend to the territories of Guernsey and the Bailiwick of Jersey, as follows:
"…the Government of the United Kingdom of Great Britain and Northern Ireland hereby extends the application of the United Kingdom's ratification of the Convention to Guernsey and the Bailiwick of Jersey, for whose international relations the United Kingdom is responsible.
The Government of the United Kingdom of Great Britain and Northern Ireland considers the extension of the Convention to Guernsey and the Bailiwick of Jersey to take effect on the date of deposit of this notification…"
On 29 June 2020, the Government of the United Kingdom of Great Britain and Northern Ireland notified the Secretary-General that its ratification of the Convention would extend to the territoire of Gibraltar, as follows: "… the Government of the United Kingdom of Great Britain and Northern Ireland hereby extends to the territory of Gibraltar, for the international relations of which the United Kingdom is responsible, the application of the United Kingdom's ratification of, firstly, the Convention and, secondly, the Protocol. The Government of the United Kingdom of Great Britain and Northern Ireland considers the extension of the Convention and the Protocol to the territory of Gibraltar will take effect on the date of deposit of this notification."
On 14 March 2023, the Government of the United Kingdom of Great Britain and Northern Ireland notified the Secretary-General that its ratification of the Convention would extend to the territory of the Cayman Islands, as follows: "… the Government of the United Kingdom of Great Britain and Northern Ireland hereby extends the United Kingdom's ratification of the Convention to the territory of the Cayman Islands, for the international relations of which the United Kingdom is responsible. The Government of the United Kingdom of Great Britain and Northern Ireland considers the extension of the Convention to the territory of the Cayman Islands shall take effect on the date of deposit of this notification."